need a little help here!

[audioguru]

Your diodes and transistors are correct.
When the diodes are added to prevent reverse voltage damage to the transistors then two resistors should be added to turn off the transistors.

 

[kchriste]

The base-emitter resistors are not really necessary with the BD679s. They already have the resistors built in:

 

[audioguru]

8k ohms is pretty low so maybe the oscillator will not work anyway.

 

[melvinspeed21]

8k ohms is pretty low so maybe the oscillator will not work anyway.

thanks sir, what do you think I have to change in the circuit?

 

[audioguru]

Please don't call everybody a SIR. A SIR was knighted by the Queen of England.
Most of us have never seen the Queen of England and have not been to India.

You can call me a dude or a stud.

 

[Sceadwian]

My father was an enlisted Navy man in the U.S. One of the favorite colorful phrases he provided me as I grew up was "Sir? Don't call me sir, I work for a living."

 

[BrownOut]

It's a sign of respect amongst one another, especially in the southern US, where I live. Has nothing to do with being knighted and that sillyness. Whenever I am speaking with someone I'm not familiar with, it's always "yes sir" and "yes ma'am"

 

[audioguru]

"yes sir" and "yes ma'am" are silliness and are related to very old customs (still used in India).
"Hey dude" and other greetings are more modern.

I always greet someone with their name. "Hi George, how are you and your family?"
I always called my teachers by their last-name, "thank-you, Mr. Smith".

 

[BrownOut]

"Hey dude" is silly surfer speak. Like, "Hey dude! Surf's up!" Sir and ma'am are formal and respectful.

PS, my father had a saying too. When he asked a question, and I replied "Yeah" He'd say, "Would it break your jaw to say sir?!"

 

[BrownOut]

To melvinspeed: I don't think your circuit will work for reasons I already stated. Try finding a better one.

 

[melvinspeed21]

really need help guys!

I am so sorry, I didn't conversate much more English, I'm a Filipino. Can anyone please configure my circuit coz I had already subitted my paper work in that project and I do really have not enough time to do another. Please help dudes..

 

[BrownOut]

You're fine melvinspeed. Some members have control issues. Do you know how your project is supposed to work? Can you name your circuit? Can you basically describe it's operation? I can offer some suggestions to make it work, but if you dont have any idea how it's supposed to work, you won't understand my suggestions. And I've tried to simulate these circuits, but LTSpice seems to have trouble for some reason.

 

[ericgibbs]

You're fine melvinspeed. Some members have control issues. Do you know how your project is supposed to work? Can you name your circuit? Can you basically describe it's operation? I can offer some suggestions to make it work, but if you dont have any idea how it's supposed to work, you won't understand my suggestions. And I've tried to simulate these circuits, but LTSpice seems to have trouble for some reason.

hi,
Post your LTS asc files, I like a challenge.

 

[BrownOut]

HI Eric. The first asc file simulates fine, but seems to take a long time for such a simple circuit. In the 2nd one, I've attempted to add output buffers, but the simulation just seems to hang up.

 

[BrownOut]

BTW, I think the OP needs to drive his globes from added buffers to get his project to work. I think connecting them in place of the Collector resistors is a bad idea.

 

[ericgibbs]

BTW, I think the OP needs to drive his globes from added buffers to get his project to work. I think connecting them in place of the Collector resistors is a bad idea.

hi,
Try these.

 

[BrownOut]

That was fast. What is the difference?

 

[ericgibbs]

That was fast. What is the difference?

hi,
I have changed the Pulsed 12V to a fixed 12Vdc and set it to skip initial start up, also delayed the 'saving data' time.

 

[BrownOut]

Thanks Dude Pulsing the 12V was my attempt to give the circuit a starting transient.

melvinspeed, here is one idea that might get you going. Q3 and Q4 were added to drive your globes, which are modeled by R12 and R9. This circuit is provided as an illustrative example of how to drive using a multivibrator. It may not be the final circuit that works in your final configuration. It's up to you to understand the principles involved and get it to work.

 

[audioguru]

I don't think the diodes should short the bases of the transistors and ruin the negative swing of the capacitors.
Instead I think the diodes should be in series with the bases.